Energy-Efficient Lighting for the Home
This guide can help consumers find their way through the wide array of energy-efficient lighting choices available today.
by Jeanne Byrne
The incandescent light bulb has been the proud symbol of good ideas since the time of Edison. Most of us have used these same pear-shaped "A-lamp" incandescents for as long as we can remember. Over the years they have helped us to cook, read, work, and play, and even have provided security and mood. But the standard A-lamp gets a "D" in energy efficiency when compared to new fluorescent (and some improved incandescent) energy-saving bulbs.
What are these energy-efficient light bulbs? How much energy do they save? What quality of light do they produce? How much do they cost? How long do they last? Where do you find them?
In the following pages we'll answer some common questions about energy-efficient light bulbs, and present the information you need to buy the best light bulbs for your home. As you read, note that the word "lamp" generally refers to the light bulb itself. When referring to fixtures, we will use more specific terms like "table lamp."
http://hem.dis.anl.gov/eehem/94/941116.html
http://www.eren.doe.gov/erec/factsheets/eelight.html
http://www-is.informatik.uni-oldenburg.de/~dibo/teaching/mm/pages/light-fundamentals.html *****
http://energyoutlet.com/res/lighting/KandB/
http://www-vms.ecs.umass.edu/~dcheney/ARC2710.html
http://www.misty.com/people/don/bulb1.html
http://www.misty.com/people/don/
How Fluorescent Lamps Work
by Tom Harris - http://www.howstuffworks.com/fluorescent-lamp.htm/printableYou see fluorescent lamps everywhere -- in offices, stores, warehouses, street corners -- even in peoples' homes. But even though they're all around us, these devices are a total mystery to most people. Just what is going on inside those white tubes?
Color Temperature and Color Rendering Index (CRI)
Color temperature is how cool or warm the light source appears. Incandescent lamps have a warmer appearance than mercury vapor yard lights, for example.CRI is a relative measure of the shift in surface color of an object when lit by a particular lamp, compared with how the object would appear under a reference light source of similar color temperature. Commonly used as references are incandescent lamps (warm light sources) and natural daylight (a cool light source). Incandescent lamps and daylight have a CRI of 100, the highest possible CRI. The higher the CRI of the light source, the "truer" it renders color.
The chart gives the CRI and color temperature of various light sources.
You can see that fluorescents come in a variety of color temperatures and CRIs. If you want to use fluorescent lamps in a room that also has incandescent lamps, consider the warmer 3000K long fluorescents or 2700K compact fluorescents. Their warmer color temperature makes them a better match for incandescent lamps.
Consider "color temperature"--how cool or warm the light source appears--when choosing lamps. The Color Rendering Index (CRI) is a relative measure of the shift in surface color of an object when lit by a particular lamp, compared with how the object would appear under a reference light source of similar color temperature. The higher the CRI of the light source, the "truer" it renders color.
http://energyoutlet.com/res/lighting/KandB/color.html
http://davem.cc.emory.edu/COLOR.HTM
http://www.gelighting.com/na/institute/understanding.html
http://www.eren.doe.gov/femp/procurement/lamp_tips.html
How to convert footcandles and lux to candelas:
Candelas are equal to the square of the distance multiplied by the number of footcandles. For example, if your meter is ten feet away from the light source and your meter reading is 10 footcandles, the equivalent candelas equals 10 feet squared (e.g. 100) times 10 -- which equals 1,000 candelas.The conversion of footcandles and lux to candelas is most accurately achieved in the context of a single point source of light measured in the dark. If the light source is diffused, you should take several readings at different angles in order to calculate an "average" candela measurement.
http://www.clubfree.com/spectra/candela/#candelas
Illuminance Conversion Formula's (Foot Candle, Lumens, Lux) - http://www.webcom.com/~legacysy/convert2/illum.html
http://www.intl-light.com/handbook/ch07.html
http://www.slcc.edu/schools/hum_sci/physics/tutor/2210/measurements/index.html
Brightness, Luminance, and Confusion
In reading many articles involving the measurement and perception of light, I found that just six photometric expressions - or "six light words" - form the nucleus of what professionals in the display business need to know. The words are those that appear most frequently in articles on displays and in government and manufacturers' display specifications. They are fundamental to the understanding of photometry. Understanding the concepts associated with these six words will create a solid foundation on which display professionals can work and grow. It will also reduce the need to call on experts for help in solving measurement problems.
LIGHT | LUMINOUS FLUX | LUMINOUS INTENSITY | LUMINANCE | BRIGHTNESS | ILLUMINANCE
http://www.crompton.com/wa3dsp/light/lumin.html
Operating Data and the Economics of Different Lamps
http://www.darksky.org/ida/info04.html
Fluorescent -
http://www.howstuffworks.com/question236.htm
PMB Electronics (Net-Tech Developments) - http://www.pmb.co.nz/fluor_1.htm
Halogen -
http://www.howstuffworks.com/question151.htm
RESIDENTS ASKED TO TURN IN HALOGEN LAMPS AND BULBS, FIRE DEPARTMENTS STRESS SAFETY - http://www.ci.shrewsbury.ma.us/electric/halogen.htm
LED -
Each light source has merits and each performs well when used in a suitable environment. The lumen-per-watt, the SI unit commonly used for measuring the total amount of light emitted by a light source per the energy input, does not accurately reflect the true efficacy of LED light sources. An LED is a directional light source and emits little or no spherical light, whereas lumen-per-watt takes into account all light emissions, including spherical, from a light source and not just what is actually accomplishing the required illumination task.
http://www.aliww.com/features.html
http://www.semiconductor.agilent.com/news/pr/15mar99.html
http://www.cetsolar.com/superdclighting.htm
http://www.hollysolar.com/lowvolt.htm
http://www.l-a-net.net/~ed/led-links.html
http://www.misty.com/people/don/ledx.html **********
Utilizing LEDs in Today's Energy Conscious World - http://www.ledtronics.com/Utilizing_LEDs/Table_of_Contents.htm **********
HID -
Improper disposal damages the environment
- Fluorescent lamps illuminate countless businesses, stores, schools and homes. HID lamps (mercury-vapor, metal-halide and high-pressure sodium) are used for street lights, floodlights and industrial lighting. Unfortunately, most of these lamps have been improperly collected as municipal waste and dumped in ordinary sanitary landfills. When broken, these lamps release mercury and other metals that damage the environment.
Used fluorescent and HID lamps may be classified as hazardous waste due to their mercury content and are thus regulated under the Resource Conservation and Recovery Act (RCRA). These regulations provide for management of hazardous wastes. http://www.epa.state.il.us/land/fluorescent-lamps/Don Klipstein's Lighting Info Site! - http://www.misty.com/~don/light.html **********
Light Pipes
U.S. Patents on daylight-pipes date back to the 1890's, however, ancient Egyptians had the idea when they lined vertical shafts with gold leaf for the purpose of reflecting daylight deep into their massive stone structures. As long as there has been dark interior rooms, there has been the concept of brightening them using some kind of conduit with which to "pipe" daylight indoors. However, until reflective technology advanced, there would be no practical daylight-pipe design.
Heliostat Lighting
http://www.redrok.com/up970331.htm#lighting
